The present invention relates to a new and improved construction of floor treating or cleaning machine, hereinafter conveniently referred to as a floor treating machine, such machine being of the type which is supported at the floor or surface to be treated by means of a work disk which is arranged beneath a substantially ring-shaped stop member and releasably coupled with a drive motor.
Floor treating machines of such type are employed for the most varied work, such as, for instance, for polishing, buffing, wiping, scrubbing, sanding, grinding, planing, spraying (with chemical agents) and so forth. These prior art floor treating machines can be basically classified into two groups, namely a first group which is employed for the thorough floor treating work and a second group employed for the maintenance work. Consistent with such subdivision there have been constructed for many years heavy, high-output floor treating machines for the thorough cleaning work and lighter, less powerful machine constructions for the maintenance cleaning work. The most commonly employed models are typically equipped with a work disk having a diameter of about 400 millimeters. Satisfying the requirements which prevail owing to the nature of the work which must be accomplished by resorting to the available equipment heretofore known in the art is extremely uneconomical and for years has only constituted a continual emergency solution. This can be already best appreciated from the aspect of the manufacturer of such equipment, since the production of two different types of machines results in smaller mass production and accordingly higher costs for each unit. Of perhaps even greater significance are the drawbacks considered from the standpoint of the user of such machine, particularly if it is appreciated that the thorough floor cleaning or treatment work -- in contrast to the daily maintenance cleaning work-- occurs at larger time intervals, possibly only once each year, with the result that the more expensive floor treating machine used for the thorough cleaning work is hardly used and therefore uneconomically employed.
Up to the present the manufacturers of such equipment have not been able to find a satisfactory solution for this problem and to offer one to the consumer. One proposal which has been made and commercialized relates to a two-speed machine which is operated at a lower rotational speed during the thorough cleaning work and at a higher rotational speed during the maintenance cleaning work. But with this solution, of course, the machines are more complicated and expensive, without really providing any increased advantages in terms of the more expensive costs of the equipment. In fact it has been found that the higher rotational speed only provides better utilization of the motor output which has been designed on the basis of the thorough cleaning work over a partial range of the maintenance work, not however over the entire range of maintenance work. Apart from the foregoing it has been found to be a further extremely disadvantageous factor that the correct selection of the rotational speed (for the purpose of optimumly utilizing the power of the motor) is extensively dependent upon the skill and "feeling" of the operator and improperly selected rotational speeds can lead to disturbances in the operation of the equipment. Due to these drawbacks preference has generally persisted for the single-speed machines.
Moreover, in an attempt to avoid the necessity of procuring two machines the users of such equipment have acquired bad habits. For instance, it has been found that the workers have used the machine intended for the thorough cleaning or treating work also for the maintenance cleaning work or, however, as more frequently was the case, the maintenance cleaning machine once per year for the heavy or thorough cleaning work and which last-mentioned type of work was much too rigorous for use with the maintenance cleaning machine. In the first case there existed on a daily basis loss in drive energy, whereas in the second case the machine was actually overloaded and thus either immediately or during the course of time broke down.